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indexing

CORE

This module contains functions used for indexing
ST_CRSFROMTEXT
ST_CRSFROMTEXT(proj4)
Description
Creates a CoordinateReferenceSystem from a PROJ.4 projection parameter string.
proj4: String input projection parameter string.
Return type
Geometry
Example
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SELECT carto.ST_CRSFROMTEXT('+proj=merc +lat_ts=56.5 +ellps=GRS80');
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-- +proj=merc +lat_ts=56.5 +ellps=GRS80
ST_EXTENTFROMGEOM
ST_EXTENTFROMGEOM(geom)
Description
Creates a Geotrellis Extent from the given Geometry.
geom: Geometry input Geometry.
Return type
Extent
Example
1
SELECT carto.ST_EXTENTFROMGEOM(carto.ST_MAKEBBOX(0, 0, 1, 1))
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-- {"xmin": 0, "ymin": 0, "xmax": 1, "ymax": 1}
ST_EXTENTTOGEOM
ST_EXTENTTOGEOM(extent)
Description
Creates a Geometry representing the bounding box of the the given Geotrellis Extent.
extent: Extent input extent.
Return type
Geometry
Example
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WITH t AS (
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  SELECT carto.ST_EXTENTFROMGEOM(carto.ST_MAKEBBOX(0, 0, 1, 1)) as extent
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)
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SELECT carto.ST_ASTEXT(carto.ST_EXTENTTOGEOM(extent)) FROM t;
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-- POLYGON ((0 0, 0 1, 1 1, 1 0, 0 0))
GEOMREPROJECT
ST_GEOMREPROJECT(geom, crsA, crsB)
Description
Transform a Geometry from The Common Reference System crsA to crsB.
geom: Geometry input geom.
crsA: CRS input crsA.
crsB: CRS input crsB.
Return type
Geometry
Example
1
WITH t AS (
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  SELECT carto.ST_POINT(3, 5) AS point,
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  carto.ST_CRSFROMTEXT('+proj=merc +lat_ts=56.5 +ellps=GRS80') AS crsa,
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  carto.ST_CRSFROMTEXT('+proj=longlat +ellps=GRS80 +datum=NAD83 +no_defs') AS crsb
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)
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SELECT carto.ST_ASTEXT(carto.ST_GEOMREPROJECT(point, crsa, crsb)) FROM t;
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-- POINT (0.00003 0.00005)
ST_MAKEEXTENT
ST_MAKEEXTENT(lowerX, lowerY, upperX, upperY)
Description
Creates a Extent representing a bounding box with the given boundaries.
lowerX: Double input lower x value.
lowerY: Double input lower y value.
upperX: Double input upper x value.
upperY: Double input upper y value.
Return type
Extent
Example
1
SELECT carto.ST_MAKEEXTENT(0, 0, 1, 1);
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-- {"xmin": 0, "ymin": 0, "xmax": 1, "ymax": 1}

formatters

measurements

Last modified 8mo ago